If you take all the numbers as gospel, accept that eating meat has a far larger carbon footprint than a plant based diet, then look at all the other things that increase your carbon footprint, you know just to get some perspective, then what you find is that having a child is a carbon footprint of over 58 tons per year but being vegan only saves 0.8 tons per year. I crunched the numbers and discovered that a meat eating person (0.82T) who drives a car (2.4T) and goes on two transatlantic flights a year (1.4-4.8) has a carbon footprint many times smaller than a vegan carless person who does not fly but who has a single child (58.6T).
You could either have one vegan being able to have a child or over 7 people eating meat, driving cars, and going on international flights.
I eat meat, I drive a car, and I go on holiday abroad twice a year (not transatlantic) but I have no kids. As such I have a carbon footprint 11 times smaller than a vegan who has a child.
Before you get to 'eat a plant based diet' in the list of the most effective ways to reduce your carbon footprint there are a few options.
1, Have one fewer child (58.6T)
2, Live car free (2.4T)
3, avoid one transatlantic return flight (1.6T)
4, Buy green energy (1.47T)
5, go from electric car to car free (1.15T)
6, eat a plant based diet (0.82T) (hooray! here we are!)
7, replace typical car with hybrid (0.52)
8, wash clothes in cold water (0.25T)
9, hang dry clothes (0.21T)
10, recycle (0.21T)
11, upgrade light bulbs (0.1T)
So, instead of giving up meat, you could almost be as green by doing cold clothes washes then hanging your clothes to dry, recycling, and getting energy saving lightbulbs.